Question

a projectile is projected such that its horizontal range is maximum.its kinetic energy at maximum heigt is 100 kJ then its initial kinetic energy​

Answer 1

Explanation:

Maximum possible range means we use θ=45

0

in the range , R=

g

u

2

Sin2θ

so the maximum height achieved will be H=

2g

u

2

sin

2

45

0

=

4g

u

2

so the potential energy at that point will be mgh=

4

1

mu

2

which is half of the KE at ground K=

2

1

mu

2

So using conservation of mechanical energy the remaining

KE at the top point we get it is K−

2

K

=

2

K